Plastic pipes made of polyvinyl chloride, polyethylene, or other suitable plastic materials are routinely used for the transport of natural gas. As can be appreciated, these pipes are arranged and interconnected as required to establish the required distribution network. Before these pipes can be welded or bonded, it is necessary that the oxide layer formed on the outermost surface of the pipe be removed. This oxide layer results from exposure of the pipe to ultraviolet light and can adversely affect the bonding process. To remove this oxide layer, a number of devices have been developed.
U.S. Pat. No. 4,114,485 to Coblitz et al discloses to an articulating device that both cuts and bevels selective lengths of pipe. The device is designed to accommodate a variety of pipe diameters by having a selectably positionable roller slide. Although adjustable, the device is not suited to continual fixed-thickness material removal from the outer circumference of an end region, or central region of a pipe. Instead, the device operates much like a conventional pipe cutter, wherein the cutting element is gradually moved radially inwards to engage the workpiece. As such, the device is not self-feeding (i.e. the pipe cannot move longitudinally), but rather requires continual alignment of the workpiece with the cutter.
U.S. Pat. No. 4,663,794 to Evans discloses a plastic pipe scraper for scraping the outside circumference of a plastic pipe. The device comprises a frame member adapted to fit over the plastic pipe, and a scraper blade pivotally attached to one end of the frame member. The scraper blade is urged to engage the plastic pipe by way of an adjustable spring means. While this device appears to be capable of scraping both end and central regions of pipe, the device is not universal (i.e. designed to fit a broad range of pipes). In engaging a pipe to be scraped, the scraper blade forms part of the engagement means. Moreover, aside from the adjustable spring means designed to urge the blade into contact with the pipe, there is no real means to firmly tighten the device on a pipe.
U.S. Pat. No. 4,825,543 to Thalmann et al discloses a cutting tool device comprising a pair of articulated arcuate strap members adapted to be clamped about a cylindrical pipe for cutting about the circumference of either an end portion, or central portion of pipe. This device lacks the ability to adjust to a wide variety of standard size pipes used in the industry. Attachment of the device to a pipe relies on a bell crank-connection to impart sufficient clamping pressure through the strap members. There is no facility to further tighten and/or adjust the clamping force of the device.
U.S. Pat. No. 6,698,321 to Oswald discloses a pipe shaver device suited for removing a uniform layer of material from the outer diameter of a pipe. The device is designed for one size of pipe (i.e. it is not adjustable to suit a variety of standard size pipes). The device also incorporates a shoulder stop that prevents passage of the pipe through the device unless a set thickness of material has been removed by the cutting blade, thus interfering with use in central regions of pipe. This device also requires that the user apply manual force in the longitudinal direction to feed the pipe through the device as there is no self-feeding or “walking” function.
From the above discussion, one can appreciate there is clearly a need for an improved pipe shaving device that is suited for use on both end regions and central portions of pipe and which is adjustable to accommodate a variety of pipe diameters.
It is therefore an object of the present invention to obviate or mitigate at least one of the above described disadvantages.